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		<title>three.js webgl - multiple renderers</title>
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		<div id="info"><a href="https://threejs.org" target="_blank" rel="noopener">three.js</a> webgl - multiple renderers</div>

		<script type="module">

			import * as THREE from '../build/three.module.js';

			let camera, scene, renderer1, renderer2;

			let mesh1, mesh2, mesh3;
			const color = new THREE.Color();

			init();
			animate();

			function init() {

				camera = new THREE.PerspectiveCamera( 20, window.innerWidth / ( window.innerHeight / 2 ), 1, 10000 );

				scene = new THREE.Scene();
				scene.background = new THREE.Color( 0xffffff );

				const light1 = new THREE.DirectionalLight( 0xffffff );
				light1.position.set( 0, 0, 1 );
				scene.add( light1 );

				const light2 = new THREE.DirectionalLight( 0xffff00, 0.75 );
				light2.position.set( 0, 0, - 1 );
				scene.add( light2 );

				// shadow

				const canvas = document.createElement( 'canvas' );
				canvas.width = 128;
				canvas.height = 128;

				const context = canvas.getContext( '2d' );
				const gradient = context.createRadialGradient( canvas.width / 2, canvas.height / 2, 0, canvas.width / 2, canvas.height / 2, canvas.width / 2 );
				gradient.addColorStop( 0.1, 'rgba(210,210,210,1)' );
				gradient.addColorStop( 1, 'rgba(255,255,255,1)' );

				context.fillStyle = gradient;
				context.fillRect( 0, 0, canvas.width, canvas.height );

				const shadowTexture = new THREE.CanvasTexture( canvas );

				const shadowMaterial = new THREE.MeshBasicMaterial( { map: shadowTexture } );
				const shadowGeo = new THREE.PlaneGeometry( 300, 300, 1, 1 );

				let shadowMesh;

				shadowMesh = new THREE.Mesh( shadowGeo, shadowMaterial );
				shadowMesh.position.y = - 250;
				shadowMesh.rotation.x = - Math.PI / 2;
				scene.add( shadowMesh );

				shadowMesh = new THREE.Mesh( shadowGeo, shadowMaterial );
				shadowMesh.position.x = - 400;
				shadowMesh.position.y = - 250;
				shadowMesh.rotation.x = - Math.PI / 2;
				scene.add( shadowMesh );

				shadowMesh = new THREE.Mesh( shadowGeo, shadowMaterial );
				shadowMesh.position.x = 400;
				shadowMesh.position.y = - 250;
				shadowMesh.rotation.x = - Math.PI / 2;
				scene.add( shadowMesh );

				const radius = 200;

				const geometry1 = new THREE.IcosahedronGeometry( radius, 1 );

				const count = geometry1.attributes.position.count;
				geometry1.setAttribute( 'color', new THREE.BufferAttribute( new Float32Array( count * 3 ), 3 ) );

				const geometry2 = geometry1.clone();
				const geometry3 = geometry1.clone();

				const positions1 = geometry1.attributes.position;
				const positions2 = geometry2.attributes.position;
				const positions3 = geometry3.attributes.position;
				const colors1 = geometry1.attributes.color;
				const colors2 = geometry2.attributes.color;
				const colors3 = geometry3.attributes.color;

				for ( let i = 0; i < count; i ++ ) {

					color.setHSL( ( positions1.getY( i ) / radius + 1 ) / 2, 1.0, 0.5 );
					colors1.setXYZ( i, color.r, color.g, color.b );

					color.setHSL( 0, ( positions2.getY( i ) / radius + 1 ) / 2, 0.5 );
					colors2.setXYZ( i, color.r, color.g, color.b );

					color.setRGB( 1, 0.8 - ( positions3.getY( i ) / radius + 1 ) / 2, 0 );
					colors3.setXYZ( i, color.r, color.g, color.b );

				}

				const material = new THREE.MeshPhongMaterial( {
					color: 0xffffff,
					flatShading: true,
					vertexColors: true,
					shininess: 0
				} );

				const wireframeMaterial = new THREE.MeshBasicMaterial( { color: 0x000000, wireframe: true, transparent: true } );

				mesh1 = new THREE.Mesh( geometry1, material );
				mesh1.position.x = - 400;
				mesh1.rotation.x = - 1.87;
				scene.add( mesh1 );

				const wireframe1 = new THREE.Mesh( geometry1, wireframeMaterial );
				mesh1.add( wireframe1 );

				mesh2 = new THREE.Mesh( geometry2, material );
				mesh2.position.x = 400;
				scene.add( mesh2 );

				const wireframe2 = new THREE.Mesh( geometry2, wireframeMaterial );
				mesh2.add( wireframe2 );

				mesh3 = new THREE.Mesh( geometry3, material );
				scene.add( mesh3 );

				const wireframe3 = new THREE.Mesh( geometry3, wireframeMaterial );
				mesh3.add( wireframe3 );

				//

				renderer1 = new THREE.WebGLRenderer( { antialias: true } );
				renderer1.setPixelRatio( window.devicePixelRatio );
				renderer1.setSize( window.innerWidth, window.innerHeight / 2 );
				document.body.appendChild( renderer1.domElement );

				renderer2 = new THREE.WebGLRenderer();
				renderer2.setPixelRatio( window.devicePixelRatio );
				renderer2.setSize( window.innerWidth, window.innerHeight / 2 );
				document.body.appendChild( renderer2.domElement );

			}

			function animate() {

				requestAnimationFrame( animate );

				// update scene

				mesh1.rotation.z += Math.PI / 500;
				mesh2.rotation.z += Math.PI / 500;
				mesh3.rotation.z += Math.PI / 500;

				const position = new THREE.Vector3();
				const color = new THREE.Color();

				let time = performance.now() / 500;

				const positions = mesh3.geometry.attributes.position;
				const colors = mesh3.geometry.attributes.color;

				for ( let i = 0, l = positions.count; i < l; i ++ ) {

					position.fromArray( positions.array, i * 3 );

					color.setRGB( 1, Math.sin( time + position.x ), Math.cos( time * 2.123 + position.x ) );
					colors.setXYZ( i, color.r, color.g, color.b );

				}

				colors.needsUpdate = true;

				//

				time = performance.now() / 2000;

				camera.position.x = Math.sin( time ) * 1800;
				camera.position.z = Math.cos( time ) * 1800;

				camera.lookAt( scene.position );

				renderer1.render( scene, camera );
				renderer2.render( scene, camera );

			}

		</script>

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